1. Field of the Invention
The present invention relates to a press-in contact to be pressed into a throughplated hole of a printed circuit board. The press-in contact includes
a contact spring or a contact pin, PA1 a middle shaft portion connected to the contact spring or pin, and PA1 a connecting pin forming an extension of the middle shaft portion, PA1 wherein the contact spring or the contact pin has in the transition area to the shaft portion a press-in shoulder, the shaft portion is provided with a slot-shaped opening whose sides are formed by legs, and wherein each end of the slot-shaped opening has an approximately parabolic configuration.
2. Description of the Related Art
Press-in contacts of the above-described type are known in the art and serve to effect solder-free electrical connections which may correspond as so-called press-in connections to DIN 41611, part 5. Consequently, the press-in contact of the above-described type is of the type EE because the press-in portion of its shaft portion forming the actual press-in pin is constructed so as to be elastic, i.e., the forces necessary for the press-in connection are applied by the deformation of the elastic shaft portion and the printed circuit board which receives the press-in contact, as mentioned in Section 3.22 of DIN 41611, part 5.
A press-in contact of the above-described type is known from German utility model G 90 04 090.2. As compared to other well known press-in contacts, in the press-in contact of this type the making of the contact in a sleeve of a printed circuit board in the pressed-in state is improved by providing the slot-shaped opening at both ends thereof with the same parabolic configuration, while the opening has a reduced width portion in the middle thereof. This counteracts an excessive, non-uniform deformation of the legs forming the slot-shaped opening, so that the legs do not have to be realigned after the pressing-in process.
However, it has been found that the pressing-in process of the known press-in contact into the printed circuit board sleeve may lead to a hole wall deformation of the tin-coated copper sleeve. This has the disadvantage that the pressing-in may produce the so-called "jet effect", i.e., copper material and tin material are pulled into the sleeve. This may even have the result that copper layers are torn off, which is a result to be observed frequently when using multilayer printed circuit boards.